A novel straw structure sandwich hood with regular deformation diffusion mode

Abstract

This work proposes an improved straw structure (ISS) sandwich hood (ISSH) to reduce the serious child head injuries caused by vehicle hood. The ISS sample is manufactured using the selective laser sintering (SLS) technique with nylon 11 material. A quasi-static compression experiment verifies the accuracy of the ISS in finite element analysis (FEA). The head injury criterion (HIC15) with the original hood and ISSH are then compared. The obtained results show that ISSH reduced the HIC15 by an average of 46.2 %. The ISSH has a regular deformation diffusion mode (RDDM), which helps to expand the energy absorption area. The ISS deformation mode is top-down layer-by-layer folding of structural layers. In addition, the impact of ISS geometric parameters on head injuries is studied. The thinner upper conical structures, larger layer heights, and material nylon 11 of the ISS contribute to the further improvement of protective effectiveness. The protective effectiveness of small-sized ISSs with connecting plates (SISC) against head injuries decreases with the increase of ISS quantity. In summary, this work provides new insights into the design of the sandwich hood for pedestrian protection, and the RDDM mechanism provides a novel direction for energy absorption.